Process for oxidizing asphalt



Patented Feb. 20, 1945 2,370,007 PROCESS FOR oxmrz no ASPHALT Donald E. Carr, Los Angeles, Calif., assignor to Union Oil Company of California, Los Angeles, Calif., a corporation of California No Drawing; Application January 18,. 1943, Serial No. 472,742

-14 Claims. (o1. lac-74) This invention relates to the manufacture of oxidized. or air-blown asphalt from. petroleum, petroleum residuum and the like.

It is Well known to produce oxidized asphalt by blowing petroleum oils, such as petroleum residua, with. air or other oxygen-containing.- gases at elevated temperatures for a suflicient period of time until the desired change in melting point is obtained. Air-blowing the petroleum oil has the effect of raising the melting. point, lowering the penetration and ductility and also lower ing the susceptibility of the asphalt to temperature changes, thus rendering the asphalt particularly suitable for roof coating, waterproofing and similar purposes requiring a bituminous material of high melting point and low temperature susceptibility. However, this older method of producing oxidized asphalt is very;tedious. and requires considerable time, often taking as much as 20 to 4.0 hours of blowing time in order to pro-,-

'duce the asphalt of desired melting point-penc tration characteristics;

It is among the objects of my invention: to provide a process for producing oxidized asphalt wherein it is possible to, accelerate the oxidation reaction time over that customary in asphalt production and at the same time producing asphalts of superior characteristics.

I have found that. air-blowing: petroleum oil in the presence of a. relatively small amount of certain types of compounds catalyzes the oxidation reaction to such. extent that the: air-blowing time is; considerably shortened. In accordance with myinvention, a relatively small; amount, i. e. 0.1 to 2% by weight of an organic complex: of a metallicsalt is added: to. the, petroleum stock tov be subjected to air-blowing and the mixture is sub.- jected to air-blowing.- in. the usual. manner, preferably at elevated temperatures of: approximately 350-559." R, until; an asphalt is produced having the desired; melting point. and penetration. Airblowing the petroleum stock in the. presence. of a. small: amount: of: the. organic complex of a metallic salt will not only shorten the; time required to produce; an. asphalt.- of' high; melting; point; but will. also. produce an asphalt of; a higher penetra tion and. ductilityfor a given; melting point than can be obtained by air blowing, under; similar conditions. the same petroleum. stock without the addition of the; organic complex o-f'a metallic salt.

Organic complexes. of metallicv salts which. may be employed in accordance with my invention includethe sludges obtained in treating petroleum fractions with metallic salts, such a metallic halides, carbonates and sulfates. I have found the sludges obtained by treating petroleum fractions: with metallic halides to beparticularly de-- sirable for this'purpose. The sludge obtained in treating a cracked gasoline with aluminum chloride. has been. found to be particularly suitable in accelerating the oxidation reaction and in producing an asphalt of superior characteristics.- Hydrocarbon stocks from which the organic complexes of metallic salts may be produced include the various hydro-carbon fractions containing hydrocarbons which are reactive'with the metallic salts and particularly containing olefinic hydrocarbons. These include cracked gasoline, kerosene, gas oil, etc., polymer gasoline, kerosene and the like and also olefins produced. from high molecular weight hydrocarbonssuch as wax, footsoil and the like. The latter are generally produced by halogenating a petroleum wax such as with chlorine at an elevated-temperature and then dechlorinating the chlorinated hydrocarbons by heating to a higher temperature to produce the olefins. The sludges obtained by treating these olefins with aluminum chlorine are useful for the purpose of myinvention.

The treatment of the hydrocarbons with the metallic salts toproduce the sludge is well known in the art. In general, this includes adding a relativelysmall amount, i. e-. 2%-10% by weight of the metallic salt to the stool:v to be treated and heating the mixture to a temperaturegenerally around IOU-600 F. Also, useful in my. process are sludges obtained by cracking petroleum hydrocarbons, preferably in the liquid phase, in the presence of metallic salts, such as aluminum chloride, sludges. obtained in the isomerization of hydrocarbons such as. butane, pentane and naphtha in. the presence of. aluminum chloride, sludges obtained in thealkylation of isoparafiins. with, olefins in the presence of such alkylating catalyst as boron trifluoride, etc.

I have found the metallic halides to be particularly suitable to treat hydrocarbons to producethe. organic complexes of the. metal salts.

These include; the aluminum. zinc,- iron, boron,

spider at its lower extremity for the introduction of air or other oxygen-containing gas. The residuum was heated to a temperature of about 280 F. and then about 1.5% by weight, based on the residuum, of an organic complex of aluminum chloride was mixed with the heated residuum. The blend was subjected to air-blowing at a temperature of about 480-490 F. for about 14.5 hours employing air at a rate of 2 cubic feet per minute per barrel of charge of residuum.

The organic complex of aluminum chloride was produced by mixing about 20% by weight of anhydrous aluminum chloride and 80% by weight of a polymer gasoline having a boiling range of about ISO-250 F. and produced by polymerizing low boiling olefins such as butylene in the presence of phosphoric acid. The mixture was then heated for about 36 hours at a temperature of about 150 F. and the resulting sludge was separated from the treated gasoline by decantation.

The oxidized asphalt produced at the end of about 14.5 hours of air-blowing had a melting point of 208 F., penetrations of 9, l7 and 32 at 32, 7'7 and 115 F., respectively, a flash point of 440 F. (Cleveland open cup), a ductility of about 3.2 cm. at 77 F. and solubilities of 99.89, 99.11 and 66.6 in carbon bisulfide, carbon tetrachloride and 82 naphtha, respectively.

For comparison, another charge of the above San Joaquin Valley residuum was air-blown under similar conditions in the absence of the organic complex of aluminum chloride to approximately the same melting point of about 208 F. This required about 23 hours and produced an asphalt having penetrations of 5, 10 and at 32, 77 and 115 F., respectively, a flash point of 445 F. (Cleveland open cup), a ductility of about 1.1 cm. at 77 F. and solubilities of 99.93, 99.92 and 63.9 in carbon bisulfide, carbon tetrachloride and 82 naphtha, respectively.

The comparative run indicates that a superior melting point-penetration-ductility relationship characteristic is obtained by air-blowing the charge in the presence of the organic complex of aluminum chloride.

The foregoing description of my invention is not to be taken as limiting but merely as illustrative thereof since many variations may be made by those skilled in the art without departing from the scope of the following claims,

I claim:-

1. A process for producing asphalt which comprises incorporating a relatively small amount of a hydrocarbon complex of a metal halide in a petroleum oil fraction and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature.

2. A process for producing asphalt which comprises incorporating a relatively small amount of a hydrocarbon complex of a metal halide in a petroleum oil fraction and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature, a hydrocarbon complex of a metal halide being produced by treating a hydrocarbon oil with a metal halide.

3. A process for producing asphalt which comprises incorporating 0.1 to 2% by weightof a hydrocarbon complex of a metal halide in a petroleum oil fraction and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature.

4. A process for producing asphalt which comprises incorporating a relatively small amount 01 a hydrocarbon complex of a metal halide in a petroleum oil fraction and commingling said oil fraction with oxygen-containing gas at a temperature of approximately 350-550 F.

5. A process for producing asphalt which comprises incorporating in a petroleum oil fraction a relatively small amount of a sludge obtained by the treatment of a hydrocarbon oil with a metal halide and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature.

6. A process for producing asphalt which comprises incorporating a relatively small amount of a hydrocarbon complex of an aluminum halide in a petroleum oil fraction and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature.

7. A process for producing asphalt which comprises incorporating a relatively small amount of a hydrocarbon complex of an aluminum halide in a petroleum oil fraction and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature.

8. A process for producing asphalt which comprises incorporating a relatively small amount of a hyrocarbon complex of aluminum chloride in a petroleum oil fraction and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature.

9. A process for producing asphalt which comprises incorporating in a petroleum oil fraction a relatively small amount of a sludge obtained by the treatment of a hydrocarbon oil with an aluminum halide and commingling-said oil fraction withoxygen-containing gas at an elevated oxidizing temperature.

10. A process for producing asphalt which comprises incorporatingin a petroleum oil fraction a relatively small amount of a sludge obtained by the treatment of a hydrocarbon oil with an aluminum halide and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature.

11. A process for producing asphalt which comprises incorporating in a petroleum oil fraction a relatively small amount of a sludge obtained by the treatment of a hydrocarbon oil with aluminum chloride and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature.

12. A process for producing asphalt which comprises incorporating in a petroleum oil fraction a relatively small amount of a sludge obtained by the treatment of cracked gasoline with a metal halide and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature.

13. A process for producing asphalt which comprises incorporating in a petroleum oil fraction a relatively small amount of a sludge obtained by the treatment of a hydrocarbon oil with an aluminum halide and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature.

14. A process for producing asphalt which comprises incorporating in a petroleum oil frac. tion a relatively small amount of a sludge obtained by the treatment of a hydrocarbon oil with aluminum chloride and commingling said oil fraction with oxygen-containing gas at an elevated oxidizing temperature.

DONALD E. CARR. 

